This invention relates to a flow divider suitable for use in a direct expansion evaporator coil as typically employed in an air conditioning system and, in particular, to a divider capable of producing a relatively equal flow distribution in each of a plurality of divided flow stream.
In many air conditioning systems, a controlled heat transfer is effective within an evaporator coil by exchanging energy between a media being cooled, typically air, which is passed over the coil surfaces and a working fluid, such as a refrigerant, which is routed through the coil by means of tubular flow circuits. Liquid refrigerant in the evaporator coil absorbs its latent heat of evaporation from the media being cooled and, in the process, is converted to a vapor at a relatively constant temperature. As the refrigerant evaporates, it's volume increases rather dramatically. In order to accommodate for this increase in volume, the circuits may be divided so that one entering refrigerant circuit is split into two or more leaving circuits.
In order to simplify the design of the evaporator, better control the movement of refrigerant through the coil, and enhance the coil's heat transfer characteristic, it is oftentimes highly desirous to produce an equal distribution in the flow of refrigerant directed into each of the divided flow circuits. Obtaining this type of equal distribution without resorting to complex downstream control circuitry has heretofore been a problem in the art. Conventionally, Y-shaped dividers, generally referred to as "sling shots" have been used to divide an entering flow of refrigerant into two or more evaporator circuits while three legged return bends, aptly referred to as "tripods", are used to divert the flow leaving one evaporator circuit into two or more circuits. Although these prior art devices serve to divide a flow of refrigerant as it enters a plurality of circuits, the distribution of working fluids diverted into each of the divided flow streams generally tends to be unequal. When this occurs, steps must be taken downstream of the divider to adjust the circuits and thus correct the system for the unequal split. One important causal factor of this unequal split is the more pronounced effect of gravity upon one of the divided flow streams than the other. This, in turn, causes a greater amount of flow to pass into the more gravity sensitive circuit thus having an adverse effect upon the operation of the evaporator coil.